Glass-ceramic cooktop construction

ABSTRACT

A smooth cooktop construction wherein a glass-ceramic panel is mounted in a frame and secured therein by means of a burner box structure which further serves to secure a control panel of the cooktop in the frame. A subassembly of electric burner elements mounted in insulators is provided in a mounting tray which is secured to the burner box structure with the insulators engaging the underside of the glass-ceramic panel. The insulators are mounted in the tray by means of sharp securing elements urged into the sidewalls of the insulators retaining the insulators in engagement with sidewall portions of the tray. This subassembly is adjustably secured to the burner box structure. A control panel is also secured to the frame by means of the burner box structure permitting facilitated installation of the control switches and indicator lights. Facilitated connection of the electrical wiring is also provided. The cooktop structure is assembled in an inverted position on a suitable assembly fixture for facilitated assembly.

Ir V i United States tet 1 [11] 3,870,862 Doner Mar. 11, 1975GLASS-CERAMIC COOKTOP CONSTRUCTION Primary Examiner-Yolodymyr Y.Mayewsky [75] Inventor: John T. Doner, Marion, Ohio s fg gffigg'g 0rFlrm wegner Stenman Mccord [73] Assignee: Whirlpool Corporation, BentonHarbor, Mich. ABSTRACT [22] Flled: June 1974 A smooth cooktopconstruction wherein a glass- [21] Appl. No.: 482,469 ceramic panel ismounted in a frame and secured Related U S Application Data therein bymeans of a burner box structure which further serves to secure a controlpanel of the cooktop in [62} g g'g g gg S 1973 the frame. A subassemblyof electric burner elements mounted in insulators is provided in amounting tray which is secured to the burner box structure with the [52]US. Cl 219/464, 219/460, 221194746613, insulators engaging the undersideof the glass ceramic I 51 I t Cl Hosb 3/68 panel. The insulators aremounted in the tray by i 452 453 means of sharp securing elements urgedinto the side- 1 le 0 earc 219/460 walls of the insulators retaining theinsulators in engagement with sidewall portions of the tray. Thissubassembly is adjustably secured to the burner box struc- [56]References Cited ture. A control panel is also secured to the frame byUNITED STATES PATENTS means of the burner box structure permittingfacili- 3,6'12,826 10/1971 Deaton 219/453 tated installation of thecontrol switches and indicator 3,612,828 0/1971 Siegla 219/ lights.Facilitated connection of the electrical wiring is 391L829 10/1971 EvansA 4 219/464 also provided. The cooktop structure is assembled in3624'352 11/1971 Demo" et 219/449 an inverted position on a suitableassembly fixture for 3,627,986 12/1971 Anderson 219/460 facilitatedassembl 3.632.983 1/1972 Dills 219/464 3,636,309 H1972 Deaton et a1.219/452 8 Claims 10 Drawing Figures 3,679,870 7/1972 Opp 219/445 lllllli41 e l a,.,...,...lllll llllllllll 24 /23 12 74 7516 38 13 37* a4 57 &219 6 I 4 ,-i -a2a 49 51 M gg 71; a5 39 a f o 53 L/ PATENTED HARI 1 I975SHEET 2 0F 4 PATENTED 3 870 862 sum 3 pg 9 This is a division ofapplication Ser. No. 412,328 filed Nov. 2, 1973, now U.S. Pat. No.3,838,505.

BACKGROUND OF THE INVENTION 1. Field of the Invention This inventionrelates to smooth surface cooktops and in particular to glass-ceramiccooktops and methods of forming the same.

2. Description of the Prior Art In smooth cooktops, a glass-ceramicpanel is provided as the heating surface with the panel being heatedfrom below by a suitable electric coil heater carried in a suitableinsulator closely subjacent the glassceramic panel. In one form of suchcooktop, a control panel is disposed alongside the cooking surface panelwith the controls and indicating lights being disposed subjacent thecontrol panel portion. An example of a cooktop utilizing such a heatercoil construction is shown in U.S. Pat. No. 3,612,829 of Jesse L. Evanset al. In the Evans et al patent, resilient means are provided forurgingheated blocks of refractory-fiber material in heat sealed cushioncontact with the undersurface of the cooking panel.

Another patent generally similar thereto is that of I Homer W. Deaton etal U.S'. Pat. No. 3,624,352 utilizing a surface temperature limitingdevice including a thermostat controlled by the temperature of thebracket flanges.

Other heating means generally of this type are disclosed in U.S. Pat.No. 2,637,800 of K. M. Hammell and US. Pat. No. 2,260,165 of E. N.Calhoun.

SUMMARY OF THE INVENTION The present invention comprehends an improvedsmooth cooktop construction which is simple and economical ofconstruction. The cooktop utilizes a number of subassemblies which maybe adjustably secured into the overall construction for facilitatedassembly. In one such subassembly, the electric heating elements areinstalled in atray by means of supporting insulators. The insulators aresecured to the tray by sharp retaining elements pressed into thesidewalls of the insulators and holding the insulators against aplurality of surfaces of the tray sidewalls. At least one of the sharpsecuring elements may be formed integrally with one of the traysidewalls.

The cooktop is assembled in an inverted position on a suitable fixture.Thus, the cooking surface panel is installed on the frame carried on thefixture. A sealing gasket may be provided about the panel and the gasketretained in association with the frame by means of the burner boxsubsequently secured to the frame.

The burner box may include a dividing wall dividing the burner box spaceinto two adjacent portions. A control panel may be mounted to the frameand secured thereto also by the burner box structure. The controlswitches and indicator light means may be mounted in the burner boxspace below the control panel. The heating coil tray may be secured tothe dividing wall.

The electric wiring of the cooktop is facilitated by means of a wiringharness package. An electric cable clamp may be attached to the burnerbox bottom for facilitating connection of the electric cable wires. Theheating elements are provided with terminals at the bottom thereofextending through the tray bottom for facilitated electrical connection.The electric terminal block providing support for the electric terminalsis secured to the tray with a single screw for facilitated installation.

Thus, the invention comprehends a cooktop construction which isextremely simple and economical of construction while yet providing thehighly desirable advantages discussed above.

BRIEF DESCRIPTION OF THE DRAWING Other features and advantages of theinvention will be apparent from the following description taken inconnection with the accompany drawing wherein:

FIG. I is a perspective view of a cooktop embodying the inventionmounted in a portion of a kitchen cabinet;

FIG. 2 is an enlarged transverse vertical section thereof;

FIG. 3 is a fore-and-aft vertical section thereof;

FIG. 4 is a top plan view of the heating coil subassemy;

FIG. 5 is a fragmentary enlarged vertical section taken substantiallyalong the line 5-5 of FIG. 4;

FIG. 6 is a fragmentary enlarged vertical section taken substantiallyalong the line 6-6 of FIG. 4;

FIG. 7 is a perspective view illustrating a first step in the assemblyof the cooktop;

FIG. 8 is a perspective view illustrating a subsequent step in theassembly thereof;

FIG. 9 is a perspective view illustrating a further subsequent step; and

FIG. 10 is a perspective view illustrating a still further subsequentstep in the assembly thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the exemplary embodiment ofthe invention as disclosed in the drawings, a smooth cooktop generallydesignated 10 is shown mounted in a portion of a cabinet 11 which,illustratively, may comprise a conventional kitchen counter cabinet. Thecooktop is adapted for selective use as a drop-in range unit, or in aset-in range, or in a freestanding range, as desired.

As shown in FIG. 1, the cooktop comprises a smooth cooktop defined by acooking panel 12 illustratively comprising a glass-ceramic panel ofconventional construction. The panel is set in a frame 13 which, asshown in FIG. 1, overlies the upper surface 14 of the counter.

The frame may include a divider strip 15 forseparating the panel 12 froma control panel 16 also set into the frame. As shown, the control panelmay include a plurality of control knobs 17 for controlling heating ofpreselected areas 18 of the panel 12 by suitable heating elements 19mounted subjacent the panel, as illustrated in FIG. 2. Control panel 16may be formed of a tempered glass material and may be provided withindicating portions 20 to be suitably illuminated for indicating theenergization of the selected burner areas 18 by correspondingmanipulation of the control knobs 17 controlling adjustable switches 21,as shown in FIG. 2.

The invention comprehends as improved cooktop construction and method offorming the same which is extremely simple and economical. Morespecifically, the cooktop construction utilizes subassemblies which areadjustably associated permitting facilitated assembly of the entire unitby means of a simple fixture. As shown in FIGS. 2 and 3, the cooktopincludes burner box means 22 including sidewalls 23, 24, 25 and 26,

and'adividing wall 27 extending across the burner box space 28 definedby the sidewalls 23-26 and dividing the space into a cooking spaceportion 29 and control space portion 30, as shown in FIG. 2. Dividerwall 27, as shown in FIG. 8, extends between front sidewall 23 and rearsidewall '24 and includes'a pair of mounting bosses 31 aligned withsimilar bosses 32 on left sidewall 25. The sidewalls may be providedadjacent their lower edges 33 with a plurality of louvers 34 for ventingthe burner box space 28.

The heating elements 19 are carried in a box-like tray 35 in cookingspace 29. As shown in FIG. 2, tray 35 includes a left sidewall 36secured to mounting boss 32 and a right sidewall 37 secured to mountingboss 31 supporting the tray adjustably under the panel 12 in the upperportion of cooking space 29.

As further shown in FIG. 2, the control switches 21 and indicatinglights 38 of control 39 are carried on a insulators 43 may be formed ofa high reflectance, vacuum formed, short fiber alumina silicainsulation. The insulators may be cast of such material to providelightweight, heat resistantinsulating supports for the heating coils.

Connecting wires 45 and 46 are brought from the opposite ends 47 and 48of the heating coil outwardly to a terminal block 49. Asshown ,in FIG.5, each terminal block 49 includes a pair of terminals 50 extendingdownwardly through the bottom wall 51 of the tray 35 for facilitatedelectrical connection to the heating coils in the assem bly of thecooktop. Each terminal block 49 is secured to the tray bottom wall 51bya single screw 52 providing furtherfacilitated assembly of the unit.

As shown in FIG. 4, each insulator 43 includes a pair of flat surfaces53 and 54 facially engaging the right angularly extending sidewalls ofthe tray 35 at the corners 55 thereof, and more specifically, engagingportions 56 and 57 spaced from the corner edge 58. The insulatorscarrying the heating coils are fixedly secured in the tray corners bymeans of sharp retaining elements 59 and 60. Retaining elements 59 maycomprise inturned tabs formed in the sidewall portions 57 of the traysidewall and projecting into the insulating material of the insulator43, as shown in FIG. 6. Retaining elements 60 may comprise turnedportions of a retaining clip 61 secured to the tray bottom 51 bysuitable means such as screw 62. Retaining elements 60 engage a portionof the insulator 43 generally oppositely of the surfaces 53 and 54 andcooperate with the retaining element 59 in locking the insulatingelements firmly in the corner portion as illustrated in FIG. .4.

As further shown in FIG. 4, the bottom wall 51 of tray 35 may beprovided with a radiating embossment 63 reinforcing the bottom wall.

As shown in FIGS. 5 and 6, the upper edge 64 of the outer wall 65 ofeach insulator 43 projects above the top edge 66 of the sidewalls of thetray 35. Thus, when the tray is mounted to the bosses 31 and 32, theupper edge 66 of the tray is spaced slightly below panel 12 when theupper edge 64 of the insulator engages the undersurface 67 of panel 12.Vertical adjustment of the tray is permitted by provision of elongatedslot-type openings 68 in the bosses 31 and 32, as shown in FIG. 3,permitting the tray to be secured to the burner box walls 25 and 27 bysuitable screws 31a and 32a with the heater assembly 41 disposed asshown in FIGS. 2 and 3.

The assembly of the cooktop is readily effected in a novel and simplemanner, as shown in'FIGS. 7-10, wherein frame 13 is firstly set on asuitable fixture 69 with the exposed trim portion 70 lowermost and witha turned flange portion 71 thereof projecting upwardly. As shown in FIG.7, the frame includes the divider strip 15. The divider strip 15similarly includes a trim portion 72 and a mounting flange porti0n73.The glassceramic panel 12 is provided with a peripheral gasket 74 andthe control panel 16 is similarly provided with a peripheral gasket 75and then placed in the frame to rest on the trim portions 70 and 72.

In the next step, as seen in FIG. 8, the sidewalls 23, 24, 25 and 26 ofthe burner box are installed on the frame inwardly of the flange portion71 to rest on the inturned trim portions 70. The dividing wall 27 ismounted to the divider strip 15 and each of the sidewalls and dividerwall is secured to the frame by suitable screws 76 to define a burnerbox assembly 77, as shown in FIG. 8.

Sidewalls 23 and 24 may be suitably slotted to pass the opposite ends ofthe divider strip 15 in assembling the burner box structure 77, asshown.

Heating unit assembly 41 is then installed in an inverted position inthe burner box space 29 to the left of divider wall 27, as shown in FIG.9.

As discussed above,,the burner. box assembly is secured in position withthe projecting edge 66 of the insulators engaging .the underside 67 ofpanel 12'and secured in place by suitable screws 31a and 32a extendedthrough the slotted openings 68 of the bosses 31 and 32. Similarly, thecontrol assembly 40 is installed in an inverted position in the controlspace 30 to the right of divider wall 27 and suitably secured to theburner box by suitable screws 78 to be disposed subjacent the con- .trolpanel 16 as shown in FIG. 2.

Wiring 79 between the heating element terminals 50, the indicator lights'38 and control switches 21 is then completed by means of a suitablecolor coded wiring harness package (not shown). The wires 80 may bebrought out through a conventional electric cable clamp 81 in a bottomwall 82 which maybe secured across the lower ends of the burner boxassembly 77 by suitable screws 83 as shown in FIG. 10. i I

Mounting of the side walls 23, 24, 25 and 26 and di vider wall 27 of theframe further serves to secure the panels 12 and 16 and the peripheralgaskets 74 and 75 thereof to the frame as illustrated in FIGS. 3 and 4.Thus, each of the sidewalls and divider wall may be provided with aturned flange 84 engaging the gasket to provide a cushioned mounting ofthe burner box and panels.

Upon completion of the subassembly of the cooktop as shown in FIG. 10,the cooktop may be removed from the fixture 69 and turned top uppermostpermitting the control knobs 17 to be installed on the switch shafts 85to complete the assembly of the cooktop.

In installations such as freestanding ranges, the bottom wall 82 of theburner box may be omitted. Thus, the cooktop is adapted for use not onlyas a drop-in unit, but also as a set-in or freestanding range unit. Theassembly of cooktops is facilitated by utilization of the burner boxwalls as the means for retaining the gasketed panelsl2 and 16 in placeon the frame. Adjustability in the mounting of the heating unit assembly41 to the burner box walls further simplifies and facilitates assemblyof the cooktop. Facilitated mounting of the heating unit insulators inthe heating unit tray further simplifies the assembly while yetproviding accurate positioning of the heating elements relative to theunderside of the heating panel 12 in the completed cooktop.

As the heating wall terminals 50 are brought out through the bottom wall51 of the heating unit, facilitated electrical connection is provided.The adjustability of the mounting of the tray permits for a lower costconstruction in obviating the need for high tolerances in the dimensionsof the heating unit element while yet a positive firm engagement betweenthe heating unit insulators and the cooking panel is assured.

The foregoing disclosure of specific embodiments is illustrative of thebroad inventive concepts comprehended by the invention.

I claim:

1. A glass-ceramic cooktop comprising:

a glass-ceramic panel;

a frame member;

gasket means around the periphery of the glassceramic panel;

burner box side means mounted to said frame and securing theglass-ceramic panel and gasket means to said frame member;

a tray having a sidewall spaced below said panel within the burner boxside means;

an insulator in said tray having an upper surface, said insulator havingsidewall means projecting above the sidewall of the tray;

an electric heating element disposed on said upper surface of theinsulator;

means adjustably securing the tray to the burner box side means forproviding abutting relationship between the upper end of the insulatorsidewall means and the glass-ceramic surface; and

a burner box bottom member cover attached to said burner box side meansenclosing the tray.

2. The glass-ceramic cooktop of claim 1 wherein said adjustable securingmeans comprises sharp elements projecting into said insulator and meansmounting the elements to said tray.

3. The glass-ceramic cooktop of claim 1 wherein said insulator comprisesa fibrous alumina silicate element.

4. The glass-ceramic cooktop of claim 1 wherein said insulator comprisesa high reflectance, vacuum formed, short fiber alumina silica element.

5. The glass-ceramic cooktop of claim 1 wherein said burner box sidemeans includes a divider wall, and said cooktop further includes acontrol panel secured to said frame by said burner box side means.

6. The glass-ceramic cooktop of claim 1 wherein said heating element andinsulator comprises a subassembly and means are provided for securingthe insulator to said tray.

7. The glass-ceramic cooktop of claim 1 wherein said insulator defines apair of flat surfaces being in perpendicular planes and faciallyengaging perpendicularly extending sidewall portions of the tray, saidinsulator being secured to said tray by sharp elements carried by thetray and projecting into said insulator sidewall.

8. The glass-ceramic cooktop of claim 1 wherein said insulator defines apair of fiat surfaces being in perpendicular planes and faciallyengaging perpendicularly extending sidewall portions of the tray, saidinsulator being secured to said tray by sharp elements carried by thetray and projecting into said insulator sidewall, one of said elementsbeing provided at one of said tray sidewall portions.

1. A glass-ceramic cooktop comprising: a glass-ceramic panel; a framemember; gasket means around the periphery of the glass-ceramic panel;burner box side means mounted to said frame and securing theglass-ceramic panel and gasket means to said frame member; a tray havinga sidewall spaced below said panel within the burner box side means; aninsulator in said tray having an upper surface, said insulator havingsidewall means projecting above the sidewall of the tray; an electricheating element disposed on said upper surface of the insulator; meansadjustably securing the tray to the burner box side means for providingabutting relationship between the upper end of the insulator sidewallmeans and the glass-ceramic surface; and a burner box bottom membercover attached to said burner box side means enclosing the tray.
 1. Aglass-ceramic cooktop comprising: a glass-ceramic panel; a frame member;gasket means around the periphery of the glass-ceramic panel; burner boxside means mounted to said frame and securing the glass-ceramic paneland gasket means to said frame member; a tray having a sidewall spacedbelow said panel within the burner box side means; an insulator in saidtray having an upper surface, said insulator having sidewall meansprojecting above the sidewall of the tray; an electric heating elementdisposed on said upper surface of the insulator; means adjustablysecuring the tray to the burner box side means for providing abuttingrelationship between the upper end of the insulator sidewall means andthe glass-ceramic surface; and a burner box bottom member cover attachedto said burner box side means enclosing the tray.
 2. The glass-ceramiccooktop of claim 1 wherein said adjustable securing means comprisessharp elements projecting into said insulator and means mounting theelements to said tray.
 3. The glass-ceramic cooktop of claim 1 whereinsaid insulator comprises a fibrous alumina silicate element.
 4. Theglass-ceramic cooktop of claim 1 wherein said insulator comprises a highreflectance, vacuum formed, short fiber alumina silica element.
 5. Theglass-ceramic cooktop of claim 1 wherein said burner box side meansincludes a divider wall, and said cooktop further includes a controlpanel secured to said frame by said burner box side means.
 6. Theglass-ceramic cooktop of claim 1 wherein said heating element andinsulator comprises a subassembly and means are provided for securingthe insulator to said tray.
 7. The glass-ceramic cooktop of claim 1wherein said insulator defines a pair of flat surfaces being inperpendicular planes and facially engaging perpendicularly extendingsidewall portions of the tray, said insulator being secured to said trayby sharp elements carried by the tray and projecting into said insulatorsidewall.